canonical: https://jentic.com/apis/audienceful.com/audienceful

# Audienceful API

Jentic publishes the only available OpenAPI specification for Audienceful API, keeping it validated and agent-ready. Audienceful is a lightweight email marketing platform aimed at writers, creators, and small product teams. The REST API focuses on the two primitives a creator workflow needs: people (subscribers) and custom fields. With six endpoints it can create, update, list, and delete subscribers, and define the custom fields used to segment them. Authentication is a single X-Api-Key header so a writing tool or no-code automation can plug in quickly.

## For AI agents

Manage Audienceful subscribers and custom fields via a single X-Api-Key header so creator tools can sync new sign-ups into an email list.

## Scope

Does not handle email sending, broadcast scheduling, or transactional templates - use for Audienceful subscriber and custom field management only.

## Capabilities

- Add a new subscriber to the list with POST /people/
- Update a subscriber's email or custom fields via PATCH /people/
- Remove a subscriber from the list via DELETE /people/
- Page through every subscriber with GET /people/ for export or sync
- Define a new custom field for segmentation using POST `/people/fields`/
- List all custom fields configured on the account through GET `/people/fields`/

## Use cases

### No-code form to newsletter sync

Creators capture sign-ups on a landing page or a Tally/Typeform form and want them in Audienceful without running a backend. POST /people/ accepts the email and any custom field values and creates the subscriber in one call. With a single X-Api-Key header the integration fits into Zapier, Make, or a serverless function in minutes.

Example prompt: Given a sign-up event with email and source fields, POST /people/ with the email and a custom field 'source' set to the form name.

### Segment audiences with custom fields

A creator running both free and paid newsletters needs to segment subscribers by plan, interest, or source. POST `/people/fields`/ creates a custom field once, and PATCH /people/ updates each subscriber's value when their state changes (for example, after a Stripe payment webhook). GET /people/ paginates the audience for any later export or audit.

Example prompt: Create a custom field 'plan' via POST `/people/fields`/, then for each existing paid subscriber call PATCH /people/ with plan='premium'.

### Bulk export and audit

When a creator needs an audit of their list before migrating tools or running a paid campaign, GET /people/ paginates the entire subscriber roster with all custom field values. The export can be loaded into a spreadsheet or pushed into a data warehouse for analysis without leaving the API.

Example prompt: Page GET /people/ until exhausted and write each subscriber's email and custom_fields to a CSV file.

### AI agent integration via Jentic

A creator-assistant agent using Jentic can sync new readers into Audienceful without storing the X-Api-Key in the agent context. The agent searches an intent like 'add a subscriber to my newsletter', Jentic returns the matching POST /people/ operation with its input schema, and the call is executed with the apikey resolved from your Jentic One instance.

Example prompt: Use Jentic search 'add a subscriber to Audienceful', load the schema for POST /people/, and execute it with email='reader@example.com' and a tag of 'beta-launch'.

## Key endpoints

| Method | Path | Description |
| --- | --- | --- |
| GET | `/people/` | List subscribers |
| POST | `/people/` | Create a new subscriber |
| PATCH | `/people/` | Update a subscriber |
| DELETE | `/people/` | Delete a subscriber |
| GET | `/people/fields/` | List custom fields |
| POST | `/people/fields/` | Create a custom field |

## Key resources

- **People** — Subscriber CRUD across the full audience with custom field values
- **Fields** — Custom field definitions used to segment subscribers across the account

## Why Jentic

- **Setup:** Wiring Audienceful by hand means handling its API-key request header for subscriber and custom-field management calls. Through Jentic you install once, import the Audienceful API from the API Directory, store the key once, and your agent calls it while Jentic injects the header.
- **Permission scoping:** Audienceful reaches people and fields through collection endpoints and request bodies rather than a resource id in the URL path, so limit the agent to the operations it needs, such as adding a subscriber or listing fields. You choose the operations it may call, so deleting people is not included unless you add it.
- **Credential handling:** Your Audienceful API key is stored once, encrypted, by your own Jentic One instance and injected as the request header at execution time. It never enters the agent's prompt, logs, or context.
- **Discovery method:** Agents search Jentic by intent such as 'add a subscriber to Audienceful', and Jentic returns the matching operation with its input schema so the agent calls POST /people/ or POST `/people/fields`/ without browsing the reference docs.

## Related APIs

- **Kit (ConvertKit) API** — Kit (ConvertKit) is the larger creator-focused newsletter platform with deeper automation.
- **MailerLite API** — MailerLite offers a similarly lightweight email marketing API with broader campaign features.
- **Stripe API** — Stripe checkout and subscription webhooks pair with Audienceful to drive paid-newsletter onboarding.

## FAQ

### Why is there no official OpenAPI spec for Audienceful API?

Audienceful publishes prose API help at audienceful.com/help but does not distribute an OpenAPI file. Jentic generates and maintains this spec so that AI agents and developers can call Audienceful API via structured tooling. It is validated against the live API and kept up to date. Get started with Jentic One, the self-hosted execution layer.

### What authentication does the Audienceful API use?

The Audienceful API uses an API key passed in the X-Api-Key header on every request. The key is generated in the Audienceful account settings. Through Jentic the X-Api-Key is held in the vault and injected at execution time, so the raw key never reaches the agent's context.

### Can I add a subscriber and set custom field values in one call with the Audienceful API?

Yes. POST /people/ accepts the email plus a custom_fields object in the request body, so a sign-up event can create the subscriber and tag them in a single round trip. PATCH /people/ updates fields on an existing subscriber.

### What are the rate limits for the Audienceful API?

Audienceful does not declare rate limits in the spec. The service is aimed at creator-scale lists, so production integrations should pace bulk imports and watch for 429 responses on the /people/ endpoints rather than push thousands of writes per minute.

### How do I sync new sign-ups into Audienceful through Jentic?

Run jentic search 'add a subscriber to Audienceful', load the schema for POST /people/, and execute it with the email and any custom field values. Jentic resolves the X-Api-Key from the vault at execution time. With pip install jentic the integration is one async call.

### Is the Audienceful API available on every plan?

API access is part of Audienceful's paid tiers. The free trial is enough to validate an integration, and once an account is on a paid plan the same X-Api-Key continues to work without scope changes.

### Can I limit what my agent is allowed to do with the Audienceful API?

Yes. Because you run Jentic One yourself, your own rules decide which Audienceful operations and credentials the agent may use. Audienceful reaches people and fields through collection endpoints and request bodies rather than a resource id in the path, so you can allow only the calls the workflow needs, such as creating a subscriber with POST /people/ or listing custom fields with GET `/people/fields/.` Destructive operations like DELETE /people/ are excluded unless you explicitly grant them.